As science progresses and sheds more light on our skin’s physiological composition and its function, we have the opportunity to use this knowledge to our benefit and take care of our skin better than ever.
For example, today we know the normal pH balance of the skin is fairly acidic with values ranging from 4 to 5.5. We also know that most cleansing agents are alkaline and can disturb the skin’s acid mantle.
All this information gives us insights into how we can use acids to help our skin restore its natural functions.
Most famously used acids in cosmetics are the alpha hydroxy acids (AHA) group, which include glycolic acid, lactic acid, malic acid, citric acid, and tartaric acid.
Their extensive application in cosmetics stems from the fact that AHAs have great bioavailability and can penetrate the skin really easily.
In terms of popularity, the AHA that reigns supreme is glycolic acid, which I’m sure you’ve heard of. But lactic acid is a close second, so let’s find out what exactly is lactic acid, how is lactic acid used in skincare, how you can use it yourself, and what benefits to expect.
Lactic acid is an alpha-hydroxy acid (AHA) which can be obtained by means of artificial synthesis as well as from natural sources. You can naturally derive lactic acid from sour milk, fruit, vegetables, and other plants, though, the lactic acid used in today’s over-the-counter skincare products and professional treatments is usually synthetically produced.
Cosmetic products use lactic acid in their formulas mostly for its exfoliating properties and anti-aging abilities. Additionally, lactic acid can make the skin softer and smoother, lighten dark spots, increase cell turnover, stimulate cell and collagen renewal, and control the skin’s natural moisture.
You can choose a topical over-the-counter treatment, professional treatment, or a stronger chemical peel with lactic acid. It’s the alpha hydroxy acid most frequently used for chemical peel products.
Even though glycolic acid is the superstar, lactic acid is believed to be gentler on the skin, which is why it has a better reputation when it comes to the sensitive skin type. It’s also considered the starter acid - ideal for people who’ve never used acids on their skin.
The alpha hydroxy acid group is water-soluble, or in other words, they love water molecules. Lactic acid specifically is extremely soluble - 1 part of lactic acid can dissolve 12 parts of water. What this means is that, as an exfoliant, when you apply lactic acid on the skin it breaks down the bonds between cells that hold the outer skin layer together. This way, when the excess build-up on the surface of the skin is removed, there’s an opportunity for newer, softer, and healthier-looking skin to the surface, leaving all the superficial imperfections in the past.
Besides helping the skin get rid of damaged and dead skin cells, dirt, and cosmetic product residue, lactic acid stimulates the production of collagen and cell turnover, making the skin more elastic, tight, younger looking, and with the ability to heal from damage faster.
There’s good news for people with sensitive skin. Lactic acid is considered gentle and can be a wonderful alternative when other stronger acids are out of the question.
Still, we’re talking about an acid with exfoliating properties, so you need to be careful - the concentration intensity is key.
Different products use different concentrations of lactic acid in their formulas. The more concentrated the product is, the more intense the effect is. You might feel a slight stinging sensation, which means it’s working - but this shouldn’t be painful and overly uncomfortable.
Before settling down, you will probably have to experiment a little to find the best product for your skin.
And, there’s always the possibility to mix lactic acid with other natural ingredients for sensitive skin and get the benefits without causing skin irritation. These are the standards you should be holding your skincare products to.
The legend says that Cleopatra bathed in milk (milk contains lactic acid) in order to get the glowing, white skin she’s famous for.
You might not be Cleopatra and you don’t have to bathe in milk, but your skin surely deserves the best. Here are some of the benefits linked with frequent use of lactic acid for the skin.
Lactic acid, just like salicylic acid, is keratolytic. This means it increases moisture in the skin by softening/dissolving the firm substance (keratin) holding the outermost layer of skin cells together. This helps the dead skin cells to fall off and also stimulates the skin to retain more water.
Lactic acid is most effective in reducing the symptoms of aging. So, don’t be surprised if you see lactic acid in most anti-aging creams and serums.
Because of the way it works on the skin, lactic acid can:
Some experts believe that lactic acid is even more effective than glycolic acid in reducing dark spots and hyperpigmentation. This is because lactic acid removes the outermost, damaged skin layer that is pigmented. This allows new and more even-looking skin to emerge on the surface. The new skin cells won’t be pigmented, but they will be more vulnerable to discoloration, so you need to protect the skin. Be extremely careful not to expose the skin to sunlight since you can make things even worse.
Our skin is a living organism that moves and stretches to fit our needs best. It usually goes back to its place, but time and external pollutants can make this process challenging. As we age, our skin loses collagen and becomes dry and saggy. Collagen is key in keeping the skin elastic and youthful. Lactic acid stimulates collagen production, which works as a preventative measure, saving your skin from becoming saggy and dull. There are many wonderful products that even use green tea and lemon extract to boost the tightening effect. One word of caution though - while they might be more effective, these products are usually harsher on the skin and should be avoided by people with sensitive skin.
Reduce the appearance of wrinkles and fine lines.
Another great benefit that comes from stimulating more collagen production is reducing wrinkles and fine lines. Wrinkles are a type of scar tissue that appears because the skin doesn’t heal as effectively as it once did. The everyday “damage” from smiling, laughing or frowning will start to show on your face because the skin becomes drier as we age. Stimulating cell turnover and collagen production regenerates the skin and helps with more effective and faster healing.
The most common reason for enlarged pores, despite genetics, is the buildup of debris inside the pores. Using alpha hydroxy acids, which include lactic acid, can help you reduce the appearance of enlarged pores by sweeping away dead skin cells, oil, and makeup residue that has built up inside pores on the skin’s surface. This is how lactic acid can help you keep your pores clean and small.
When it comes to acne problems and blemishes, lactic acid is not as appreciated as salicylic acid, benzoyl peroxide or witch hazel, but there are a couple of ways it can help diminish the frequency of breakouts. Lactic acid holds anti-bacterial properties and prevents excess oil, debris, and dead cells to enter the pores. This can be really beneficial for problematic and inflamed skin and can reduce the development of pimples and even aid in healing acne breakouts faster.
Keratosis pilaris is the fancy name of the common "chicken skin" bumps that usually appear on the back of the arms. The rash can also appear on the thighs, cheeks, and buttocks.
Keratosis pilaris happens when a buildup of keratin clogs the pores, causing the bottom of the pore to get larger. The skin gets irritated and hair is often trapped in the pore.
If you are in your teens, there’s a pretty good chance you already know what are we talking about although keratosis pilaris can occur at any age.
Lactic acid breaks down the plug of skin cells that build up around the hair follicle, and help the enlarged pore dissolve and get rid of excess keratin.
This is why it’s no surprise that lactic acid is the key ingredient in over-the-counter topical solutions for keratosis pilaris.
We mentioned that lactic acid is gentler than other AHAs, but remember that it’s still a powerful factor. Symptoms like redness, itching, burning, and peeling are not uncommon. They are even considered typical if you are using an alpha-hydroxy acid on your skin for the very first time.
If the intensity of the symptoms mentioned above are mild and go away on their own after an hour or two, there’s no need to worry - you’ll be okay.
In rare cases, when the symptoms persist for more than a few hours, or they’re causing you great discomfort, you should consult with your doctor and avoid using lactic acid in the future.
As with all AHAs, lactic acid can make the skin more sensitive to sunlight. This is one of the most important things you should consider before deciding to apply lactic acid on the face.
The dead skin cells on your face might irritate your skin or clog your pores, but they’ll also protect the new and vulnerable skin cells from damaging UV light. After treating the skin with lactic acid, dead skin cells are stripped away and your skin is exposed.
Never leave the house without applying sunscreen. Experts recommend using SPF 30 or higher on a daily basis.
Have in mind that the skin sensitivity can continue for about two weeks after you have stopped using lactic acid products.
There are a lot of people wishing for a bronze tan, but when your skin is vulnerable and overly sensitive, you should be really careful - a nasty sunburn can bring you a lot of brown spots, wrinkles, and even scars.
There are many over-the-counter topical treatments for various skin conditions, like eczema, psoriasis, and rosacea which use lactic acid in its formulation. Always be aware of the ingredient list on the product before purchasing.
Although this might indicate that lactic acid is relatively safe to apply when battling such conditions, some experts advise against it, as it’s known to irritate the skin even further in some cases.
If you fall into this category it’s crucial that you consult with your doctor or dermatologist before applying a product that contains lactic acid.
You can find lactic acid in many cosmetic products: peels, creams, lotions, masks, and cleansers.
In order for them to be able to act on the skin and produce the above-mentioned benefits, the final products should have a formula with a pH between 3 and 4. Before reaching the market, the products are tested for a safe pH (from 3 to 4.5) because of the possibility of being too acidic.
The typical concentration of over-the-counter products is between 5 and 12% of lactic acid.
Professional treatments and some peels can have much higher concentrations. The higher the concentration, the stronger its effect on the skin. Not only in terms of benefits but also in increasing the possibility of irritation and sensitivity.
The good news about lactic acid is that experts believe that making the skin sensitive can be minimized, or even eliminated if the formulation contains naturally soothing ingredients.
Nevertheless, it’s really important to remember that you shouldn’t use lactic acid pure and undiluted because it’s highly acidic and can lead to skin irritation and skin burns.
Lactic acid skincare products can either exfoliate or hydrate the skin, depending on the formulation and concentration.
So, you can use lactic acid products like moisturizing creams and serums or use their exfoliating properties and go for a peel treatment.
Many products use lactic acid in low concentrations. If you find a product with low concentrations of lactic acid you can definitely use that product as a moisturizing agent for the skin. It’s actually really common for brands to use lactic acid in their serums and moisturizers, even when the formula doesn’t exfoliate the skin.
Lactic acid will hydrate the skin because it’s a humectant and it reduces the trans-epidermal loss of water through the increased production of oils and fats within the skin.
Hell, you should go and check your moisturizer - maybe there’s lactic acid in its formula. And, if there’s not, don’t worry. There are plenty of other great active ingredients it can contain.
In higher concentrations, lactic acid is used as an exfoliant. It works on the surface layer of the skin by stimulating cell turnover, reducing pigmentation, evening out the skin tone and brighten the appearance of the face.
Because it’s gentler on the skin than other AHAs, it’s advertised even for sensitive skin types, although you should be careful.
You can also find lactic acid as an option in professional peels, which come in extremely high concentrations. If you have sensitive skin, but you still want to try a professional peel, lactic acid would be the best choice. Still, consult with your dermatologist before taking action.
Whether you choose a product with a low concentration or one with a higher concentration of lactic acid, make sure get one with a high-quality formula enriched with antioxidants and vitamins that soothe and complement the effect of lactic acid on the skin.
Yes and no.
Yes, because lactic acid is the gentlest acid of the AHAs group and can be a wonderful alternative for people with sensitive skin - for whom glycolic acid is out of the question.
It works on oily as well as dry skin because it encourages the outermost layer to peel off, taking away dead skin cells.
Additionally, lactic acid is known for regulating the skin’s pH balance which can exfoliate and help the skin stay moisturized at the same time.
But, if you have extremely sensitive skin you should be careful. At the end of the day, it’s a really acidic ingredient which can cause mild irritation, redness, and burning sensations.
If you have oily skin you can use products with stronger lactic acid formulations that are meant to exfoliate the skin.
If you have dry or sensitive skin, it’s best to start with a product with low concentrations of lactic acid and use it as a moisturizer.
But, maybe you don’t fall into these categories and you are facing some common skin problems. It’s normal to be asking yourself - is it okay to use products with lactic acid in such cases?
The answer is yes, lactic acid can help fight off many imperfections.
If you are facing frequent acne breakouts, have acne scars, wrinkles, fine lines, or brown spots and discoloration you should go for a product with higher concentrations of lactic acid. Just, make sure you do a patch test first, and try the product on a small but affected area. See how your skin is going to react. The last thing we want to is to irritate skin that’s already inflamed.
Knowing more about the skin’s physiology helps us understand how alpha hydroxy acids, and in this case, lactic acid, can provide so many benefits.
Today, lactic acid is widely used in cosmetics and professional skincare treatments for a variety of issues. Lactic acid can make the skin softer and smoother, reduce hyperpigmentation, increase cell turnover, stimulate collagen renewal, shrink pores and make the skin appear tighter.
It’s gentler on the skin compared to other AHAs, and it’s usually recommended for people with more sensitive skin that can’t handle stronger acids.
But, there are some drawbacks. Lactic acid can also irritate the skin and make it sensitive to sunlight, so you should be careful.
Depending on the concentration, lactic acid can nourish and moisturize the skin or help by exfoliating it. If it’s your first time using lactic acid it’s best to start with a high-quality product with lots of vitamins and antioxidants, as well as a low concentration of lactic acid and see how it goes from there.